Help upgrading lighting on 75 gallon - Lighting

mattmathis · 11-05-2009, 10:50 AM

Hi, I have a 75 gallon tank that I am currently doing a "makeover" on. And I need help with my lighting situation. I'm trying do decide whether to go with T5HO or Power compact. And how much WPG to do. Because I don't want to have to run co2. I will be dosing excel.

I've read that T5HO get more light into the tank than compact fluorescent, even if the watts are higher on the compact. And that T5HO run cooler than power compact. Is that true? If so it's the way to go for me.

Also, I don't want to run pressurized CO2 so what should I aim for in WPG?
I want to grow plants like ludwigia, bacopas, blyxa, and maybe some hairgrass.

The current T5HO 2X54 fixture, combined with the 40 watt T12 I have now would give me right at 2WPG. Can I grow those plants with that? I know I can't run the current T5HO 4x54 without CO2.

Thanks for your help!

Newt · 11-05-2009, 03:43 PM

A 48" 54watt T5HO linear bulb has about 30% +/- light intensity than a 55 watt CF.

GP1 · 11-06-2009, 09:28 PM

2wpg will be fine for those plants except for the hairgrass which you probably need more light for.
Yes the T5HO will put out more light per watt than CF's & will run cooler.
If you are using Excel then you should be able to use the T5HO's that you have. Excel is a liquid form of carbon that is supposed to be used instead of injected co2, so you shouldn't have any algae issues from lack of carbon. Personally I would rig a DIY co2 system though as if done right can provide fantastic results & cost you heaps less than Excel will in the long run.

MrSanders · 11-09-2009, 02:27 PM

Quote:

Originally Posted by Newt

A 48" 54watt T5HO linear bulb has about 30% +/- light intensity than a 55 watt CF.

Just curious where you got this info from Newt? I have a 75g also and an upgrading from 4 x 65watt CF to T5 lighting and have been debating between a 4 and 6 bulb fixture. if 30%+/- per bulb is correct that is basically like saying a 4 bulb T5 fixture would be like having over 6 65watt CF bulbs, correct? If so im guessing a 6 bulb T5 fixture would be pretty much unmanageable and a waste of money.

Newt · 11-09-2009, 04:06 PM

I used the rough lumen average of the 55watt CFs I know as well as the same info for various T5HOs. Simple calc from there.

MrSanders · 11-10-2009, 09:18 AM

Thanks, good info!

With that being said, depending on how the reflectors are in the 2 x 54watt T5 fixture your looking at mattmathis, I would think the T5's alone would be more than enough, you may even want to look into a fixture with 2 cords so you can run a longer photo period with a midday burst.